Device for unscrewing and withdrawing pipe



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1 May 927 c. R. EDWARDS DEVICE FOR UNSCREWING AND WITHDRAWINCT PIPEFiled Nov. 18. 1921 May 10, 1927.

c. R. EDWARDS DEVICE FOR UNSCREWING AND WITHDRAWJINGPIPEw Filedmm 18,1921 2 Sheets-Shegt 2 Patented m 10, 1927.

7 CHARLES R. EDWARDS, OI HOUSTON, TEXAS.

DEVICE FOR UNSCREWING AND WITHDRAWING PIPE.

Application filed November 18, 1921. Serial No. 516,173.

This invention relates to new and useful improvements in an unscrewingdevice for pipe joints.

One object of the invention is to provide a device of the characterdescribed adapted for the purpose of unscrewing and withdrawing sectionsof a pipe which may become stuck in a well bore.

Another object is to provide a device of this character which can beoperated to back off, or unscrew joints of stuck pipe through theinstrumentality of a stem orstring of pipe whose sections are connectedby right hand threads, thus dispensing with the necessity of keeping onhand a string of left hand threaded pipe. The device may be employedalso for unscrewing and withdrawing casing, tubing, drill rods and thelike.

A further feature resides in the provision of a device of this characterwhich can be readily detached from the stuck pipe and withdrawn in casesaid' pipe cannot be unscrewed.

A still further feature resides in the provision of a pipe unscrewingdevice capable of being used in a bore in which casing is set; or in anopen hole, that is, in a hole without casing.

A still further feature of the invention resides in the provision of apipe pulling device whereby an upward pull may be exerted on the pipe tobe pulled as the device is being operated to unscrew a sectionorsections of said pipe, to the. end that the threads connectin thesections of the pipe to be pulled will e relieved of the weight, or apart of the weight of the sections above each joint so that the threadswill more readil unscrew and it is clear that the threa s of anyparticular joint will thus be subjected to less strain than the threadsof the joint above it, since they will carry less load and the string ofpipe being removed will thus be more llable to unscrew at oneof itslower joints thus usually accomplishing the removal of a long string ofsectionsvof the pipe to be recovered.

With the above and other objects in view the invention has particularrelation to certain novel features of construction, operation andarrangement of parts an example of which is given in this specificationand illustrateddn the accompanying drawings, wherein-:

Figure 1 is a vertical sectional view of the lower part of the device.

Figure 2 is a vertical sectional view of the upper part thereof.

Figure 3 is a transverse sectional view taken on the line 33 of Figure1.

Figure 4iv is a transverse sectional view taken on the line 4-4 ofFigure 1.

Figure 5 is a transverse sectional view taken on the line 5-'-5 ofFigure 1, and Figure 6 is a fragmentary sectional view.

Referrin now more particularly to the drawings t e numeral 1' refers tothe upper section of a tubular enclosed casing em-. ployed and thenumeral 2 refers to the lower section thereof, said sections beingfitted together so as to form a close fitting joint 3,

The

but being independently rotatable. upper end of the section 1 is closedby a cap 4 screwed therein, and formed with a central bearing 5 in whicha hollow shaft 6 rotates. The upper end of this shaft is threaded forengagement with the reducing collar 7, to which the stem is attached,

through which the devicemay be rotated from the ground surface. Thelower end of the shaft 6 carries annular flange 8 which works againstthe under side ofan inwardly extending annular flange 9 carried by thelower section 2.

Seated in bearings in the casing there is a spider 10 through thecentral bearing 11 of which the shaft 6 extends. This spider may bemade. into two sections for easy assembling and has opposing bearings12, 12 and 13, 13 spaced apart which receive the shafts 14, 14 andbetween the bearings 12 and 13 on each side the shafts 14 are providedwith spur pinions 15, 15 which work in sockets provided for them inspider 10 shown in Figure/1 and are in mesh with the internal annularrack face 16 of the section 2. Said spur pinions 15 are likewise in mesh,with a spur gear, face 17 into which the opposing sectlon of the shaft6 is formed.

The upper ends of the shafts 14 also work hearings in the section 1 andcap 4, and

preferably made of.two sections for easy assembly, and said ends of saidshafts, between said bearings, carry spur pinions 21, 21 which worksnugly in bearing pockets provided for them and are in mesh with thespur gear 22 into which the opposing section of the shaft 6 is formedand are also in mesh with the internal rack face of an annularsleeve-like friction member 23 which fits closely within the section 1and frictionally engages the same. Pivoted on the shafts 14 are theelongated links 24, 24, which work in a corresponding direction, and thefree ends of these links are pivoted to opposing dogs 25, 25, said dogsbeing" pivoted at opposing points to the inner wall of the section 1, bymeans of the bearing rods 26, 26. The operation faces of said dogs whichengage with the pipe or walls of the bore may be serrated or otherwiseformed so as to more readily engage with said casing or wall of thebore.

The lower end of the section 2 is provided 4 with internal threads intowhich the grapple or, fishing tool maybe secured. This tool 50 may be ofany conventional form and consequently has not been shown. Usually itconsists of a threaded tap, which may be screwed into or over thesection of pipe to be unscrewed and withdrawn. left hand threads so thatit will turned to the left. The fishing tool or grapple is keyed in thesection 2 as shown in Figure 6. I

The device may be first attached to a string of pi e whose sections areconnected by means collars or fittings having right hand threads, andthen let down into the bore until the fishing tool contacts with theThis tap has upper end of the section of the stem'to be unscrewed. Thestring to which the device is attached is then rotated toward the'rightwhich willcause the spur inions 15, to turn toward the left, as inicated by arrows in Figure 4. The section 2 will be temporarily heldagainst rotation, during this movement on account of the friction of thefishing tool with the pipe on which it is in contact, and the section 1will be held against rotation by reason of its friction with the section2 and with the friction member 23.

r The section 1, being thus held, will cause the spur pinions 15 totravel around the rack face 16 in the direction indicated by arrows inFigure 4, thus forcing the links 24 and the dogs 25 outwardly throughthe wide slots 27, 27 which are cut through opposing sides of thesection 1, causing said dogs to engage with the casing wall, or in theabsence of easing, with the walls of the bore. And

the section 1 and spiders 10 and will thus.

be held firmly against rotation in the bore. A continued rotation of theshaft 6 will be transmitted through the spur pinions l5 engage when thestuck pipe, and rotated backwardly, thus unscrewing the same from thesection underneath, and when unscrewed the same may be withdrawn fromthe bore.

Loosely pinned, at one end, to the dogs are the platelikehoods,28, 28loosely mounted, at one end, to the corresponding rod 26. Each hood hasanarcuate slot 29 cut therethrough, through which the upper end of thecorresponding pintle 30, connecting the link 24 and the dog 25, works.As

the dogs 25 move outwardly the pintles engage against the outer ends ofthe slots 29 and car the hoods outwardly, into theposition indicated bydotted lines in Figure 5,

and said hoods are stopped by the enga ement of the upturned lugs 31,carried y the free endsthereof, with the wall of easing 1, at the upperends of the slots 27. The hoods will thus prevent the collection ofearth or other formation underthe dogs to prevent their closing.

In some cases it is necessary to detach the device from the stuck pipe,in case the same cannot be unscrewed or withdrawn. The

construction permitting the release of the device in such cases will nowbe described.

The shaft 6 has a tubular liner 32 extending therethron h, and slidabletherein.

The upper end of t is liner is threaded into a plan er 33 which works inthe collar 7. The p unger is formed of two sections, screwed together,and between the sections there is clamped the cup 34 forming a. closefit in the collar 7. The plunger is limited in its upward movement bythe ringlike nut 35 which is threaded into the collar 7.

This collar has a port 36 beneath the plunger to permit the escape ofwater as the plunger moves downwardly. The plunger has restricted waterpassa eways 37 and 38 to permit the passage of water into the liner 32.

There is a late 39 threaded into the lower end of t c section 2 whichcarries a central stufling box 40, and above this plate there is a disc41 which is seated on the coil spring 42. This spring rests on the plate39 and surrounds the tubular guide43 which works through the stuffingbox and into the upper end of which the lower end of the liner 32 isseated. Anchored to opposingthe section 2 above the disc 41. The upperends of the dogs are inwardly turned and normally aligned above themarginal notches 47, 47 of the flange 8. \Vhen it is desired to releasethe unscrewing device from the stuck pipe the stem 6 is first rotated tothe left to release the dogs and the water in the stem is put underpressure which will force the plunger 33 and liner 32 down wardly thuscompressing the spring 42 and rotate to the right with stem, 6; sincethev stem 6 and section 2 are now locked together as a unit, andtherefore lock the pinions 14 against rotation about their axes,

- thus locking together sections 1 and 2.

1V hile thus rotated the dogs 25 having been forced back, by the slightbackward turn i of the stem 6 into released position within the casingthe fishing tap will be unscrewed from the stuck pipe and the entiredevice may then be withdrawn. If water pressure is not available astring of tools, or other weight, maybe let down onto the plunger 33 toforce it downwardly for the purpose above explained.

It is further obvious that the tool may also be varied as to itsmechanical structure,

- and still be the same tool in use and results,

but only changed in form.

While what I now consider a preferred form of the tool has been shownand described, I reserve the right to make such modificationsandmechanical changes therein as may be found desirable so long as they arecomprehended within the scope of the appended claims.

Vhat I claim is 1. A device of the character described including twoindependently rotatable members, a driving shaft, means operativelyconnecting said shaft with one of said members, whereby, the latter maybe rotated reversely, with. respect to the shaft rotation, engagingmeans carried by the other member and actuated'by said rotating meansinto engagement with the walls of a'bore, whereby said last mentionedmember is anchored against rotation and means for locking said membersagainst relative rotation.

2/ A device of the character described in- I eluding two independentlyrotatable members, a driving shaft having bearings in said members,means operatively connecting said shaft with one of said members wherebythe latter is "rotated from the shaft, engaging devices carried by theother member and actuated by said means into engagement with the wall ofa well bore whereby said last mentioned member'is anchored againstrotation, and means arranged to be actuated by fluid or other pressureto lock said members against relative rotation.

3. A device for unscrewing pipe in a well bore, including a casingformed of two indepcndcntly rotatable sections, a driving shaft,extending through the casing and having bearings in the respectivesections thereof, engaging members carried by one of said sections anannular member infrictional engagement wIth the last mentioned section,

means operatively connecting said shaft with said engaging members 'andwith said friction member, saldmeans being actuated by said shaft toforce said engaging members into engagement with the walls oftheborewhereby the section carrying the same is anchored agaInst rotation, andthe continued rotation of said shaft thereafter operating through saidmeans to' rotate the' other section reversely with respect to thedirection of the rotation of said shaft.

4. A device for unscrewing pipe in a well bore, including a casingformed of two indcf pendently rotatable sections, a driving shaftextending through the casing, engaging dogs carried by one section ofthe casing, means operatively connecting said shaft with said dogswhereby the rotation of the shaft relative tothe casing will actuatesaid dogs into engagement with the well bore, and means through whichthe said sections may be locked to rotate as a unit.

5. A device of the character described including two independentlyrotatable members, a driving shaft, means operatively connecting saidshaft with one of said members whereby the latter may be rotatedreversely with respect to the shaft rotation, engaging means carried bythe other member and arranged to engage with the walls of a well v bore,whereby said last mentioned member anchored against rotation, and meansfor locking said members against relative rotation.

6. A deviceof the character described including two independentlyrotatable members, a driving shaft. means operatively connecting saidshaft with one of said members 1 whereby the latter may be rotatedreversely with respect to the shaft rotation, engaging means carried bythe other member and arranged to engage with the Walls of a well borewhereby said last mentioned member is anchored against rotation, andmeans arranged to be actuated by pressure to lock said members againstrelative rotation.

7. A device of the character described including two independentlyrotatable members, a driving shaft, means operatively connecting saidshaft with one of said members whereby the latter may be rotated re-'versely with respect to the shaft rotation, engaging means carried bythe'other member I and arranged to engage with the walls of a' well borewhereby said :last mentioned member may be anchored against rotation,and protecting hoods arranged over said engaging means.

8. A device of the character described including two independentlyrotatable members, a driving shaft, means operatively connecting theshaft with one of said members whereby the latter may be rotatedreversely with respect to the shaft rotation, engaging means carried bythe other member and arranged to be projected out into engagement withthe wall of a well bore whereby said last mentioned member may beanchored against rotation and protecting hoods arranged to cover saidengaging means, from above, when said means are in projected position. II

9. A device for unscrewing and withdrawing pipe from a well bore,including a driving member, an anchorable member, means whereby saidanchorable member may be anchored, and released, a driven member, a"releasable grapple attached to saidvdriven member, means whereby saiddriven member may be rotated reversely so as tounscrew the omts of saidpipe, and operative means whereby said grapple may be detached from apipe in the bore. k

10. A device of the character described including a driving member, ananchorable member, operative means for actuating said anchorablemember,'a driven member, operative means through which said driven mem-,

ber may be driven from the driving member, a grapple carried bythedriven member, means for releasin said grapple, said device being formedwith a fluid, passageway through which pressure may be exerted' toactuate said releasing means.

11. A device of the character described including a rotatabledriving'member, an anchor, o erative means whereby said anchor may esecured against rotatlon, a driven member, operative means through whichsaid driven ,member is. rotated from the driving member, said meansincluding gears having both ends mounted in bearings formed in the sameelement-of the device.

12. A device of the character described including a driving member, ananchor, operative means whereby said anchor may be fixed in position inthe well bore, or released, a driven member, operative means throughwhich said driven member may be rotated reversely with respect to thedriving memher, the contact of said driving member with the lastmentioned operative means, being integral with the driving stem of thedriving member, and means whereby the said driving and driven membersmay be interlocked so as to revolve as a unit.

13. A device for removing pipe and the I like from a well bore,including a driven member, a driving member rotatably mounted in saiddriven member, operative means through which the driven member isrotated reversely with respect to the rotation of the driving member, ananchor, means whereby said anchor may be fixed in position in a wellbore, or released, a grapple actuated from the driven member, and meanswhereby said grapple may be detached from a struck pipe in a well bore;1

14. A'device of the character described including a driving member, ananchor, means whereby said anchor may be fixed in a well bore, orreleased, said 'means including engaging elements having toothedengaging faces, a driven member and means through which said drivenmember may be rotated reversely or conversely. with respect to therotation of the driving member.

15. In an unscrewing device of the character described, a grappling toolsecured thereto, means through which the grappling tool is secured inplace, said means preventing the detachment of said grappling tool fromsaid' device, and means whereby said grapple may be rotated either tothe left or to the right.

16. In an unscrewing device of the character described a grapple securedthereto, a key preventing the detachment of the grapple from the device,and means whereby said grapple may be released from the pipe while thepipe is stuck in a well bore.

17. In an unscrewing device of the character described, an anchoringmember having toothed engaging projections.

18. In an unscrewing device of the character described, driving inionshaving both ends fitted in bearings ibrmed in the same element of thedevice.

' 19. In an unscrewing device of the character described. drivingpinions supported throughout their entire length in bearings, held inalignment as a unit construction.

20. In an unscrewing device of the char acter described a driving memberformed with an integral driving gear, a grapple, means through whichrotation may be imparted in. either direction to said grapple from saiddriving member and means through which the parts of the device may beinterlocked 'to rotate as a unit.

21. In an unscrewing device of the character described a driven memberhaving a driving gear formed with gear teeth therein, a grapple adaptedto be rotated in either direction through said teeth and meansv throughwhich the device may be locked together to rotateas a unit.

. 22. In an unscrewing device of the character described, a grapple, ahousing member havingan internal gear formed integrally therewith andthrough which said grapple may-be rotated and means through which thegrapple may be locked against rotation by said gear, whereby the entiredevice may be rotated as a unit, and the grapple released from the pipestuck in a well bore.

23. In an unscrewing device of the character described, the combinationof a driving member, a driven member and an anchorable member, onehaving pinions and formed with pockets in which said pinions rotate, agrapple carried by one of said members and operative means whereby thegrapple may be attached to or detached from a pipe in a well bore, andmeans through which the said members may be interlocked to rotate. as aunit.

24. In an unscrewing device a driving member, a driven member and ananchorable member, one of which is formed with pockets, pinions formedwith pinion shafts and pinion teeth located in the pockets of saidmember, said pockets forming bearings for said shafts, the other members(being formed with gear teeth with which said pinions are in mesh, andmeans through which said members may be locked together to rotate as aunit.

25. A device ofthe character describedineluding two independentlyrotatable members, means for anchoring one of said members againstrotation, a driving shaft and means for locking said members againsrelative rotation.

26. A device for unscrewing pipe in a well bore including adriving-member, two rotatable members associated therewith, meanswhereby one of said rotatable members may be anchored a ainst rotation,means through which the ot er of said rotatable members may be rotatedreversely with res act to the driving member, a grapple carriedby themember last named and meanswhereby the grapple carrying member and thegrapple may be rotated in the same direction as the driving member whensupported by said driving member.

27. A device for unscrewing pipe'in a ,well bore including an anchorablemember,

means whereby said anchorable member may be anchored against rotation, adriving member, a driven member, a grapple carried by the driven member,means whereby said driven member may be rotated reversely whilesupported by said driving member andmeans adapted to interlock thedriving-member and driven member whereby the entire device may berotatedas a unit.

28. A device for unscrewing plpe and the like in a well bore andincluding an anchorable member, a driving member formed with a stem, adriven member, a grapple carried by the driven member, means wherebysaid driven member and grapple may be rotated reversely with respect tothe rotation of the stem while supported through said stem andinterlocking; means Where y said driven member and grapple may be lockedto rotate as a unit with the stem.

29. In an unscrewing device of the character described, pinions, asupporting member having bearings for said pinions, and also formed withhearing like pockets, against the walls of which the outer ends of thepinion teeth contact for support.

30. In an unscrewing device of the character described, driving pinionshaving end bearings, and located in pockets whose walls form bearingsfor the pinion teeth.-

In testimony whereof I have signed my name to this specification.

CHARLES R. EDWARDS.

